Fluid lines for heating, ventilation, and air-conditioning (HVAC) systems in motor vehicles have traditionally been formed of metal due to the relatively high pressures of the fluids contained therein. However, there is a continuing effort in the automotive industry to reduce weight of individual vehicle components in order to improve overall vehicle efficiency.
In an effort to minimize weight, plastic fluid lines have been considered as one alternative to metal fluid lines. However, plastic fluid lines are typically configured having a radial sealing means to facilitate quick connection. Radial sealing means, such as o-rings, are known to have higher leakage rates compared to axial sealing means, such as gaskets. Accordingly, axial sealing means are preferred in order to minimize leakage.
Although axial sealing means provide improved sealing over radial sealing means, axial sealing means are more likely to experience reduced effectiveness over time when used in conjunction with plastic fittings. In order to maintain a sufficient seal, an axial sealing means must be compressed in an axial direction between opposing surfaces of fittings. However, plastic fittings are susceptible to material creep, and an initial compressive force applied during assembly of the fittings may decrease over time as the plastic fittings “relax” as a result of the material creep. Thus, although axial sealing means provide superior initial performance compared to radial sealing means, axial sealing fittings are more susceptible to failure when used with plastic fittings.
Accordingly, there exists a need in the art for a means of providing an axial sealing means between plastic fluid lines, wherein the axial sealing means is not affected the material creep of the plastic fittings.